100K megohm DC probe

Posted on Jul 19, 2012

A 741 op amp is used with 100% ac and dc feedback to provide a typical input impedance of 1011 ohm and unity gain. To avoid hum and rf pickup the input leads should be kept as short as possible and the circuit should be mounted in a small grounded case. Output leads may be long since the output impedance of the circuit is a fraction of an ohm

100K megohm DC probe
Click here to download the full size of the above Circuit.

With no input the output level is indeterminate. Including Rl in the circuit through lowers the input impedance to 22 M.

Leave Comment

characters left:

New Circuits



Popular Circuits

Variable zener diode
Automatic blind hooked up to existing projector screen using Arduino
continuity tester circuit
remote control using the ne 555 and lm 567
circuit 9 second countdown power on
DIY Li ion battery charger w adjustable shut off current
5 minutes time delay
L6203 DC motor controller circuit
mechatronics Design
A Dual Temperature Display With Humidity Measurement
VHF Overtone Oscillator
A control two water supply frequency control circuit a
F733 integrated amplifiers common emitter - common base wideband amplifier circuit